Differentiate between the restricted approach boundary and the limited approach boundary.

• A. The restricted boundary is the closest safe distance to live parts that only qualified personnel with protection can approach; the limited boundary is a larger distance that unqualified personnel must stay beyond unless properly protected.
• B. The restricted boundary is larger distance; the limited boundary is the closest safe distance.
• C. The restricted boundary is outside the building; the limited boundary is inside the control room.
• D. The restricted boundary and limited boundary are the same.

Answer: (A)

The concept here is how close you can get to exposed energized parts and who is allowed there. The restricted approach boundary is the closest safe distance to live parts. Within this zone, only qualified personnel who have received the proper training and are equipped with the required protective measures can approach or work. The arc—and shock—hazards are highest here, so access is tightly controlled.

The limited approach boundary is farther out. It marks a larger zone where access is still restricted, and unqualified personnel should stay outside unless they are properly protected and procedures are in place. This boundary provides a second layer of protection, ensuring that anyone who does enter has the appropriate PPE and safety controls for the hazard level.

In short, the restricted boundary is the nearest zone and is for trained, protected workers; the limited boundary is a larger zone that requires proper protection to enter.